{ "id": "2010.15451", "version": "v1", "published": "2020-10-29T09:49:14.000Z", "updated": "2020-10-29T09:49:14.000Z", "title": "Compactness of commutator of Riesz transforms in the two weight setting", "authors": [ "Michael Lacey", "Ji Li" ], "categories": [ "math.CA" ], "abstract": "We characterize the compactness of commutators in the Bloom setting. Namely, for a suitably non-degenerate Calder\\'on--Zygmund operator $T$, and a pair of weights $ \\sigma , \\omega \\in A_p$, the commutator $ [T, b]$ is compact from $ L ^{p} (\\sigma ) \\to L ^{p} (\\omega )$ if and only if $ b \\in VMO _{\\nu }$, where $ \\nu = (\\sigma / \\omega ) ^{1/p}$. This extends the work of the first author, Holmes and Wick. The weighted $VMO$ spaces are different from the classical $ VMO$ space. In dimension $ d =1$, compactly supported and smooth functions are dense in $ VMO _{\\nu }$, but this need not hold in dimensions $ d \\geq 2$. Moreover, the commutator in the product setting with respect to little VMO space is also investigated.", "revisions": [ { "version": "v1", "updated": "2020-10-29T09:49:14.000Z" } ], "analyses": { "keywords": [ "riesz transforms", "commutator", "weight setting", "compactness", "little vmo space" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }